An antagonist of adenosine A₃ receptor blocks NECA-induced profibrotic markers.

<p>The particular adenosine receptor subtype involved in profibrotic activation was recognized by using selective pharmacological antagonists for each receptor subtype, in conjunction with the general agonist NECA (5 μM). The induction of the markers fibronectin (A) and α-SMA (B) in HK2 cells, was evaluated by western blots. Selective antagonists were DPCPX (30nM) for A₁, ZM241385 (10nM) for A_2A, MRS1754 (50nM) for A_2B and MRS1220 for A₃ (10nM) receptor subtypes. The upper images show representative western blot detections of marker content in total protein extracts (50 μg) from treated HK2 cells. The blocking effect was assayed in HK2 cell cultures in 5mM (left white bars graphs) or 25mM (right black bars graphs) D-glucose. The graphs represent the mean ± SD of the ratio between immune signals of fibronectin or α-SMA vs β-actin. The ratio in HK2 cells without any pharmacological modulator was normalized to 1. * <i>P</i> < 0.05 versus untreated cells, # <i>P</i> < 0.05 versus NECA, n = 6.